1. Field of the Invention
The invention relates to an adjustment structure of garden shears. More particularly, the invention relates to an adjustment structure having a simple structure and being effective for aligning handles.
2. Description of Prior Art
FIG. 7 shows the adjustment structure of handles in a prior art; an end of outer handle 81 of the handle 8 is disposed with a fastening member for the outer tube 82, the fastening member for the outer tube 82 allows a base member 83 to fit through, so that said base member 83 can be rotated on the fastening member for the outer tube 82; said base member 83 is joined with a rod 84 with square cross section, and a carrier member 85 is fitted on said rod 84; said carrier member 85 has a square opening 851 for said rod 84 to fit through, thus making carrier member 85 rotate along with said rod 84 when it is rotated.
The carrier member 85 has a protruding pole 852, the end of protruding pole 852 near said carrier member 85 has an off-centered section 853, said off-centered section 853 is fitted with an off-centered block 86 shaped as an ellipsoid, and a hook portion 854 in the shape of a loop is disposed on the other end of protruding pole 852.
The inner tube 87 being fittable into the outer tube 81, and one of its end is disposed with a fastening member for the inner tube 88, said fastening member for the inner tube 88 has a through opening 881 for the protruding pole 852 of said carrier member 85 to fit through, and it is fastened and secured onto said fastening member for the inner tube 88 by the use of hook portion 854 on the protruding pole 852, thus making said carrier member 85 rotatable on said fastening member for the inner tube 88.
In the structure described above, said carrier member 85 begins to rotate when said base member 83 is rotated and in turn makes rod 84 rotate as well, as a result, the off-centered section 853 on said carrier member 85 is also rotated, thereby pushing the off-centered block 86 against the inner wall 811 of the outer tube 81, as shown in FIGS. 8 to 9; the friction generated from pushing the off-centered block 86 against the inner wall 811 allows the inner and outer tubes 87 and 81 to be aligned.
However, because the adjustment structure of the handles are more complex; the off-centered block 86 is made of plastic, and also compounded by the fact that the off-centered block 86 is pushed against the inner wall 811 of the outer tube 81 on only one tilted lateral side to achieve alignment; the off-centered block 86 becomes prone to contortion after a period of usage. As a result, the holding strength of the off-centered block 86 becomes insufficient over time, and thus it is necessary to improve the adjustment structure of the handles in a prior art.